#include <iostream>
#include <utility>
using std::cout;
using std::cin;
using std::endl;

int g_num = 7;
int&& return_() {
    return std::move(g_num);
}
void test() {
    //  &return_();//errno
    int&& ref = 4;
    cout << &ref << endl;
}
int main() {
    test();
    return 0;
}